High resolution (50 mu)2- and 3-dimensional imaging of snap frozen pancreas shows in feasibility studies distinctive localized signals from NADH(P)H and flavoprotein (Fp) reduction and hemoglobin concentration increases in response to glucose challenges. This result encourages comparison of images in response to titrations with glucose and leucine in order to differentiate the response of mitochondrial and cytosolic NADH(P)H. A further distinction is afforded by time-resolved imaging of redox changes; it is expected that cytosolic responses will precede mitochondrial (Fp) responses and these time separations will be confirmed by glucose/leucine comparisons. Identification of beta cell responses will be confirmed by histopathology of tissue sections processed and microtomed from the tissue block which the last optical scan is made. It is expected that these snap frozen imaging studies will afford a rationale for future minimally invasive optical evaluation of beta cell function in vivo base upon Method 2, Flying Fluorescence and Methods 3, NIR Transabdominal Imaging.